The present invention relates to an automatic transmission for a vehicle and, more particularly, to a stamped pump cover for a fluid pump disposed within an automatic transmission.
As is well known, motor vehicles typically include three basic components to effect movement of the vehiclexe2x80x94an engine, a transmission, and at least a pair of driven wheels. The function of the transmission is to transmit the mechanical energy produced by the engine to the driven wheels. More specifically, engine torque and speed are converted in the transmission in accordance with the tractive power demands of the vehicle.
Generally, a conventional automatic transmission includes a torque converter (as described above); fluid pressure-operated multi-plate drive or brake clutches; one-way clutches in conjunction with the frictional units; transmission controls, such as valves for applying and releasing elements to shift the gears (instant of shifting); and a transmission fluid pump for circulating transmission fluid to the various assemblies of the transmission. An example of an automatic transmission may be found in commonly-assigned U.S. Pat. No. 4,875,391, entitled xe2x80x9cElectronically-Controlled, Adaptive Automatic Transmission System,xe2x80x9d issued on Oct. 24, 1989 to Leising et al. This patent is hereby incorporated by reference.
Transmission fluid pumps typically include an outer gear with internal teeth that operates within a bore of a pump housing. An inner gear having external teeth, cooperative with the teeth of the outer gear, is disposed within the outer gear. These pumps typically include large, machined plates having means for securing the inner and outer gears. It is typically necessary to maintain tight tolerances in the prior art design to insure the pump remains leak-proof. Moreover, a plurality of seals are commonly used between various members and fasteners to maintain this leak-proof condition in the pump.
However, more recently, with the popularity of sport-utility (SUV) and offroad vehicles, there is a need in the relevant art to provide an ever-smaller vehicle transmission capable of minimizing vehicle weight, cost, and NVH (noise, vibration, and harshness), yet capable of maximizing durability and life of the transmission.
In accordance with the broad teachings of this invention, a pump cover for use in a transmission of a vehicle having an advantageous construction is provided. The transmission of the vehicle includes a transmission housing and a fluid pump disposed within the transmission housing. The fluid pump includes a pump housing defining an outer recess. Similarly, the transmission housing defines an inner recess. The pump cover comprises a generally circular plate having a centrally disposed aperture. The generally circular plate defines an outer portion and an inner portion. The outer portion of the generally circular plate is adapted to engage the inner recess of the transmission housing. Likewise, the inner portion of the generally circular plate is adapted to engage the outer recess of the pump housing. Thus, the generally circular plate cooperates with the transmission housing and the pump housing to enclose and seal a fluid volume adjacent the fluid pump, thereby minimizing the need for fluid seals within the fluid pump.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.